Gas operated automatic revolver



E. l. WESTMORELAND 3,045,556

GAS OPERATED AUTOMATIC REVOLVER July 24, 1962 3 Sheets-Sheet 1 Filed Oct. 7, 1959 INVENTOR. I EDWARD WEsrMmaA/vo ATTORNEY y 1962 E. I. WESTMORELAND 3,045,556

GAS OPERATED AUTOMATIC REVOLVER Filed Oct. 7, 1959 INVENTOR. Qfianmo Mama/HAND 5 ATTORNEY rubrmwm E502 July 24, 1962 E. I. WESTMCRELAND 3,045,556

GAS OPERATED AUTOMATIC REVOLVER 3 Sheets$het 3 Filed Oct. 7, 1959 INVENTOR EDWARD WESTMORELA/VD ATTORNEY United States Patent Ofifice 3,45,556 Patented July 24, 1962 3,045,556 GAS OPERATED AUTGMATIC REVOLVER Edward I. Westrnoreland, 30 Newfield St., Plymouth, Mass. Filed Oct. 7, 1959, Ser. No. 844,989 8 Claims. (61. 89191) This invention relates to improvements in automatic hand guns and particularly to the provision of a new automatic revolver operated by utilizing part of the gas pressure of the exploding cartridge to cock the gun and prepare it for firing.

Automatic pistols utilizing a spring-pressed cartridge magazine are well known, but it is an accepted fact that the revolver type action in hand guns makes possible a much better balanced and designed weapon than any of the presently known automatic pistols. The revolver can be safely carried with a cartridge in the firing position and the first shot can be readily fired by the use of one hand only; in the case of a mis-fire, the next cartridge can be in position for firing easily and without requiring the use of both hands. The revolver is basically a much simpler and sturdier weapon, its disadvantage heretofore being that its action is not automatic.

It is a major object of the invention to provide an automatic revolver of the simplest construction with a minimum of moving parts, with all moving parts traveling the shortest possible distance, and so designed that the shock of gas operation does not impose excessive strain on any of the moving parts.

Another object is to provide a hand gun in which the mechanism is placed in such a manner that a superior balance is obtained, with the thumb line higher than is possible in the case of automatic pistols or hand guns, thus minimizing the recoil efiects.

Still another object is to provide a weapon of the type described using practically all pivoted parts, and having practically no sliding parts, which greatly minimizes friction and facilitates an easy action.

It is also an objectof the invention to provide an automatic revolver which can be carried with a cartridge in the firing chamber in complete safety. Another desirable feature is that different cartridge loads can be used in the same weapon; for example, an ideally designed hand gun can be readily chambered for the 0.375 magnum cartridge, which is a heavier cartridge than it has heretofore been possible to use in any commercial automatic pistol, and this chambering would also make the use of all the various .38 caliber cartridges feasible with only a minor diiference in the speed of the automatic action.

According to the invention, the gas recoil is transmitted through a piston arrangement by a camming action to a specially designed cocking lever which cocks the hammer on its rearward stroke, and ratchets the revolver cylinder into firing position on its return stroke, by spring action, rather than by direct transmission of force from the gas piston, thus minimizing impact and breakage on the relatively delicate mechanical parts. The trigger is provided with an escapement which checks the hammer cocking movement and prevents a full automatic action. The pressure of the trigger finger holds the hammer latched in cocked position after firing each shot by engaging a hammer notch with a slight negative angle. Upon releasing the trigger, the negative angle of the engaged hammer notch forces the trigger out, the trigger cocking arm then engaging the cocking notch of the hammer, which is now set for firing. This makes possible in an automatic hand weapon a direct trigger engagement with the hammer firing notch, and permits an ideal trigger pull to be utilized, that is, one having substantially no appreciable slack.

The specific nature of the invention, as well as other objects and advantages thereof, will clearly appear from a description of a preferred embodiment as shown in the accompanying drawings, in which:

FIG. 1 is a side elevation view of the gun partly in section, showing the parts in the safety position and uncocked;

FIG. 2 is a top plan view of the gun shown in FIG. 1;

FIG. 3 is a detail view, partly in section, showing the inter-relation of the trigger and hammer, with part of the cocking lever;

FIG. 4 is an end view of the cylinder with the ratchet and spline shaft removed, showing the fixed inserted cylinder spline and ratchet guide pins;

FIG. 5 is a plan view of the cylinder hand or ratchet with the leaf spring removed;

FIG. 6 is a detail view of the ratchet and spline shaft unit;

FIG. 7 is an end view of the ratchet shown in FIG. 6;

FIG. 8 is a side elevation similar to FIG. 1, showing the mechanism at the time of automatic full cocking, just as the bullet leaves the pistol muzzle;

FIG. 9 is a side elevation of the frame with the frame guide plates removed, showing the cylinder pawl and cylinder pawl spring, with the hammer blocking bar in position;

FIG. 10 is a front view of the weapon;

FIG. 11 is a side view of the frame size plate prior to assembly and brazing on the frame;

FIG. 12 is a cross-sectional view of the frame taken on line 12l2 of FIG. 9;

FIG. 13 is an end view of the cocking lever and the incorporated rear sight;

FIG. 14 is a perspective view of the same element, in order to make its construction more apparent;

FIG. 15 is a plan view of the blocking bar;

FIG. 16 is a detail view of the cylinder pawl and the left section of the cocking lever showing the cam engagement which releases the cylinder pawl from its cylinder notch during cooking action of the cocking lever;

FIG. 17 is a detail perspective view of the cocking lever return spring and guide;

FIGS. 18 and 19 are perspective detail views of the hammer link and hammer thrust lever; and

FIG. 20 is an enlarged detail view of the rear end of the cocking drive floating piece.

Referring to FIG. 1, which shows the weapon in its normal "safe condition, the barrel 2 is fixed to the frame 1 (see also FIG. 9) in the usual fashion. The cocking lever 3 is provided, which is pivoted on shaft 5. The hammer 4, better shown in FIG. 3, is also pivoted on shaft 5 coaXially with the cocking lever, but independently movable thereon. In addition to the body 4- of the hammer there is a hammer head 4A which engages the firing pin 8 during the firing operation to drive the pin against the action of spring 10 to fire the cartridge.

Trigger 6 is pivoted on trigger pivot shaft 7 and is {biased in a clockwise direction with reference to the shaft by leaf spring 6A. Trigger arm 6B normally clears the cylindrical portion 4B of hammer 4, but when the trigger is pulled and the hammer is in the position shown in FIG. 3, the hook on the end of arm 6B can move upwardly to engage the hammer notch 4B and in this position prevents return rotation of the hammer to the firing position. When the trigger pull is released, the hammer 4 rotates slightly in the counter-clockwise direction until the sear arm 6C of the trigger engages the notch 4C of the hammer to retain the hammer in cocked position ready for firing. When the trigger is again pulled, sear arm 6C is disengaged from notch 40 to permit the hammer to continue its counter-clockwise rotation, as will be described below, to fire the weapon.

The cocking lever 3 is provided with a sight 3A notched into its upper edge. This can be used in cooperation with the usual front sight 2E to aim the weapon, since the cocking lever is always in the position shown in FIG. 1 when the gun is 'being fired. Integral with the cocking lever 3 is a channel plate 3B providing a channel 3C having a pin 3D therein to receive the end of cocking lever spring guide 11 as best shown in FIG. 8. The cocking lever spring guide 11 is urged by compression spring 12 and through its engagement with pin 3D, to bias the cooking lever in a counterclockwise direction, it being noted that the line of the cocking lever spring guide passes sufficiently to the right of the axis of pivot shaft to provide the necessary torque for the purpose. A similar hammer spring guide 13 is also provided in the hamdle, which is pivotally fastened at 15A to hammer thrust lever 15, which in turn is pivotally fastened to the frame by hammer thrust lever pivot shaft 16. The other end of lever 15 is notched as shown at 15B to engage pin 17A of hammer link 17, separately shown in FIG. 18, which is fashioned in the form of a crank element and is pivotally fastened at point 17B to the body of the hammer. It will thus be seen that as the hammer 4 is rotated in a clockwise direction from the position shown in FIG. 1 to the position shown in FIG. 8, the hammer innk pulls the hammer thrust lever 15 around in a counter-clockwise direction against the compressive force of hammer spring 14. However, it will be noted that this linkage floats in the position of FIG. 1, when points 5, 17, and 17 are in line, and that the connection between the notch 15B and pin 17A can be disengaged.

At the moment the gun is fired, the cocking lever 3, as previously noted, is in the vertical position as shown in FIG. 1. When the weapon is fired, high pressure gas from the explosion is metered through small passage 2A into the gas chamber 2B (FIG. 8) and exerts pressure against the gas piston and shaft unit 38, driving the stern rearward against buffer spring stop 41. Piston 38 is provided with a gas seal as shown at 39, and a gas piston return and bufler spring 40, to both take up the shock and to return the piston to its initial position. In its rearward motion, the shaft 38A engages the cocking drive shaft 35, and drives this against the action of its return and buffer spring 36 to move the cocking drive floating piece 34 to the rear; this piece has a cylindrical body 34A and a crosshead 34B in T-shaped relation thereto as best shown in FIG. 20, to provide a bearing surface against the coacting cammed surface portion SE of cocking lever 3, to rotate the cocking lever in a clockwise direction about its pivot 5. Since this action takes place practically simultaneously with the pulling of the trigger, the trigger is still in the retracted position shown in FIG. 8, and immediately after the firing of the cartridge by the hammer 4, the hammer is thus again returned into the cocking position in preparation for another shot. However, at this time the trigger 6 is still retracted, since the above described action is practically instantaneous. The hammer would therefore immediately return to again fire the weapon, since there has not been time for the finger pressure to be released. To prevent this, the hook at the end of trigger arm 6B is provided, because in the retracted position of the trigger this hook now engages the notch 43 to prevent the hammer from returning. As the trigger pressure is released, these elements are disengaged with the help of the negative angle of engagement at 4B, but now the sear arm 6C engages the notch 4C to retain the hammer in the cocked position.

As soon as the gas pressure is dissipated through port 2C, which occurs very rapidly, the cocking drive shaft return spring 34 and gas piston return and butfer spring 40 return the piston mechanism to the position in FIG.

l, leaving the cocking lever 3 free to return to its normal position under the influence of its spring 12.

Pivotally attached to the cocking lever 3 at pivot point 3B is the hand or cylinder rotating ratchet 19, which is biased counter-clockwise by leaf spring 19A bearing at its free end against the frame, and is carried back to the position shown in FIG. 1 by the return motion of cocking lever 3. Hand 19 engages the usual ratchet 20 provided in the cylinder 26 to rotate same a step each time the cocking lever is operated.

The cylinder is normally 'held aligned with the barrel by a cylinder pawl 23 pivotally mounted on pivot shaft 25 (see FIG. 12) fixed to the frame, and biased in a clockwise direction by coil spring 24. The conventionally bevelled rear edge of cylinder 26 is provided with a series of index notches 26A, corresponding to the number of chambers in the barrel. Cylinder pawl '23 is normally biased by spring 24 into engagement with one of these notches, to maintain the chamber in accurate alignment with the barrel. The face 23A of the cylinder pawl is shaped as a cam, cooperating with a corresponding cam surface 3B on cocking lever 3, to rotate the cylinder pawl counter-clockwise whenever the cocking lever is operated, to thus release the cylinder pawl from its engagement with the index notch 26C and permit the cylinder to rotate by the ratcheting action of hand 19 as the cocking lever 3 returns to its normal position. It will be noted that this return of the cocking lever to the position shown in FIG. 1 also releases the cylinder pawl 23, but this release does not occur until after the hand 19 has begun to rotate the cylinder; therefore, pawl 23 remains "biased against the bevelled edge of the cylinder, and falls into the next indexing notch as soon as the cylinder is rotated far enough, first striking side 26E of the notch 26A to positively stop the cylinder.

As best shown in FIG. 9, the cylinder pawl 23 also has an arm 23B, the end of which engages safety block 18, which slides in a groove in the frame into the position to block the return motion of the hammer when the safety pawl is not resting in one of the index notches. When the cylinder pawl 23 is nested in one of the index notches, it has moved sufliciently far in a clockwise direction under the pressure of spring 24 so that the safety block is carried by arm 23B out of the path of the hammer head, to permit firing operation. Thus the hammer 4 is rendered safe from striking the firing pin 8 should the hammer by any means be released, except when the cylinder is in the proper firing position. This renders it impossible for the hammer 4 to strike the firing pin 8, which could fire a cartridge that was not in eX- act alignment with the barrel, with dangerous consequences.

It will be noted that the hammer 4 can also be cocked and released independently of the cocking lever 3, by thumb action. To facilitate this, a small knurled knob or lateral projection 4A is provided (FIGS. 2 and 8). In case of a misfire, knob 4A can be used to re-cock the hammer without advancing the cylinder, so that the same cartridge can be fired again; also, knob 4A can be used to re-set the cocked weapon to the safety position by pulling the trigger, with the thumb held on knob 4A to prevent firing, and then gently easing the hammer back to its floating position, shown in FIG. 1.

Assuming that the pistol is being held for firing in the hand, in the condition shown in FIG. 1, that is, in the fully loaded and uncooked position, to fire the first cartridge, the thumb is used to cock the hammer by placing it on the cocking lever spur 3A and pulling the hammer back clockwise around pivot 5 until the sear arm 60 rests in the hammer notch 4C, into which it is urged by the action of spring 6A. The pistol is now cooked, and can be fired by pulling the trigger 6, which causes it to rotate counter clockwise around pivot 7. This releases the hammer 4 which is driven counter clockwise around pivot position 5 by the thrust of the compressed hammer spring 14, as

previously described. The firing pin 8 is driven by the hammer against the cartridge primer Which is in alignment with it and thus fires the bullet.

An important feature of the hammer assembly is that at the time of firing, the hammer 4 is floating, as the hammer link 17 has ceased to exert a counter clockwise thrust on the hammer, and the assembly is at dead center on pivot shaft 5. As the hammer 4 actually strikes the firing pin 8, its momentum carries it past dead center to drive the firing pin into the cartridge primer and to check the hammer against its stop surface of the frame. During this period the hammer link 17 has actually slightly reversed in its travel and in so doing actuates hammer thrust lever counter clockwise around pivot pin 16 (see FIG. 1) causing a corresponding compression of the hammer spring 14.

As the hammer energy is absorbed in the firing of the cartridge, this slight compression of the hammer spring 14 in releasing its tension aids in a positive rebound of the hammer. Thus in the automatic action that follows as the bullet leaves the muzzle area of the pistol, causing rearward motion of the gas piston unit 38 and in turn actuating the cocking lever 3, the moment of impact is greatly reduced because the hammer 4 is at this time rebounding in the clockwise direction also.

In the rear case of a cartridge misfire, as the hammer energy is absorbed in the striking of the cartridge primer, the slightly compressed hammer spring 14 in releasing its tension tends to move the hammer 4 clockwise and to aid in the hammers rebounding action as it returns to its safety position at the dead center area. The firing pin 8 is now back in its normal position, being actuated by its return spring It) which was compressed during the firing cycle by the force of the hammer as it drove the firing pin forward.

From the original uncooked position of FIG. 1, the pistol can also be cocked by an alternative method which would be used, for example, in the case of a misfire. The thumb of the hand holding the pistol is placed on the spur 3A of the cocking lever; the lever is pulled fully back, and carries the hammer 4 as shown in FIG. 8 to rotate the hammer clockwise around pivot 5 until the rotation is checked by the frame stop. Note that this counter-clockwise motion has charged the hammer spring 14 and also the cocking lever spring 12. From this stop position the thumb is released from the cocking lever position allowing the cocking lever return spring 12 to drive the cocking lever clockwise around pivot 5 and back to its return position as shown in FIG. 1. At the beginning of this return motion, the hammer 4 is released from contact with the cocking lever 3 as the hammer notch 45 latches cocked on the trigger sear arm 63. At the beginning of the original thumb cocking action of the cocking lever, the cocking lever cam 3B (see FIG. 16) is moving clockwise and as it engages the cylinder pawl camming area 23A the cylinder pawl begins to release its engagement from its cylinder notch 26A as shown in FIG. 8, and completely releases just before the end of the clockwise rotation. The hand 19, which is attached to the cocking lever 3, has been moving upward during the clockwise rotation of the cocking lever, until it ratchets into its next succeeding notch of the ratchet spline unit 2% as the clockwise motion is completed. At this stage, the cocking lever return spring 12 drives the cocking lever 3 counter clockwise around pivot 5. At the' start of this motion, as the cylinder pawl 23 is in a released position from its cylinder notch 26A, the cylinder 26 is free to rotate counter clockwise by the downward motion of the hand 19. As the hand returns to its original position shown in FIG. 1, the next succeeding chamber of the cylinder is carried into alignment with the barrel and exact alignment is assured by the indexing action of the cylinder pawl 23, which falls into the next succeeding notch when this alignment is reached. In the usual case of a six-chambered cylinder, the rotation is, of course, 60 for each of the above-described operations. It is to be noted that at all times when the cylinder pawl 23 is out of its corresponding cylinder notch or is not fully indexed, the safety block 18 is raised by the counter clockwise motion of the cylinder pawl, and thus blocks the hammer 4 from striking the firing pin 8 should the hammer accidentally be released.

The above-described method of hand cocking is always used in the event of an automatic misfire, as this method revolves the cylinder 26 and aligns a new cartridge in the firing position. The action of the mechanism in the manual cocking operation is identical with the automatic cocking action, the only difference being that the cocking lever 3 is actuated clockwise in the automatic operation by the rearward movement of the cocking drive floating piece 34, rather than by manual thumb action.

In the automatic action, the hammer notch 4B always engages the hammer arm '6B, as previously described, while the hammer is in the retracted position, which action does not occur with the manual cocking operation. It should be noted that there is a slight negative angle of engagement between the hooking surfaces of notch 43 and arm 6B, so that they do not tend to remain hooked by themselves, but the hammer tends to exert a slight force to urge the trigger arm 63 out of the notch 43, which allows the firing trigger arm 60 to latch lightly into the hammer notch 40 to complete the cocking action in preparation for the next shot.

For the purpose of cleaning and disassembling, the gun is also provided with a gas chamber end plug 42 which provides a removably threaded means for adjusting the effective size of inlet gas port 2A, and also can be entirely removed to permit disassembly of the gas piston and shaft mechanism.

Cylinder 26 is mounted on the usual cylinder crane 28 which is pivoted at 28A to swing the cylinder out of the gun into cartridge loading position. Cylinder crane retaining pin 29 locks the cylinder firmly in firing position, and can be released by pressing the unlocking piece 32 against spring 31; this piece is fastened to pin 29 by means of pin 33 so that the two move together as a unit. The cylinder is provided with the usual ejector plate 29, which also carries the ratchet mechanism for rotating the cylinder as previously described. This plate is fixed to ejector shaft 20A, which is splined externally to fit splines 20C of the cylinder (FIG. 4) so that the cylinder and shaft rotate as a unit. Shaft 20A is threadedly engaged with tube 21 which holds cocking drive shaft spring 36. A removable split ring retainer 37 or any similar suitable means is used to retain the cocking drive shaft under spring compression in tube 21. The ejector return spring 22 may be retained within the crane shaft 28G. Annular groove 26F is provided in the cylinder 26, and retaining pin 27 permits the cylinder to rotate but not to move axially. This pin can be removed or inserted when the shaft 20A is out of the cylinder. Thus the entire cylinder assembly can be readily disassembled for cleaning or repair. It will be noted that the drive shaft is in effect broken into three parts 38A, 35, and 34A, which are abutting, but that shaft 35 is part of the cylinder assembly and so can be swung out through the side opening 2D when the cylinder is sw ung out on its crane for reloading or inspection, and that the hand 19 has a rounded nose to prevent hanging up when the crane is pivoted open. It will also be noted that the gas drive is accomplished directly through the center of the cylinder, which permits a compact and rugged construction, yet the revolver can be loaded in the usual fashion to which users of such weapons are accustomed.

The firing mechanism is also of simple but sturdy construction and can be readily disassembled with a minimum of tools. The entire weapon is made with a minimum of expensive sliding parts, using mostly pivoted working components which can easily be made to a high degree of accuracy and reliability. The gas piston drive operates on the firing mechanism only through a cam contact which can be designed to give substantially uniform acceleration during the drive action, to thus eliminate early breakage and wear of parts due to sudden shock and hammering, which would otherwise be produced. Instead of driving the cylinder directly, spring pressure is stored up to subsequently perform this action, thus further diminishing the shock and resultant wear on the moving parts.

It will be apparent that the embodiments shown are only exemplary and that various modifications can be made in construction and arrangement within the scope of my invention as defined in the appended claims.

I claim:

1. An automatic revolver comprising a frame carrying a barrel, a rotatable cylinder mounted in said frame and having a plurality of chambers successively aligned with said barrel as the cylinder is rotated, and a hollow handgrip portion rigidly fixed to said frame; a gas cylinder communicating with said barrel by a small port, a gas piston reciprocally mounted in said cylinder, a buffer and return spring means biasing said piston forwardly, a cocking drive means driven by said piston during its rearward motion, a first pivot means mounted on said frame, a thumb-actuable cocking lever pivotally mounted on said pivot means and spring means normally biasing said lever to a forward position, a cam surface on said lever engageable by said cocking drive means to pivot said cocking lever rearwardly against its normal bias, a forwardly spring-biased hammer engageable by said cocking lever during its rearward motion to move said hammer into cocking position; and trigger means having a scar portion for engaging said hammer in said cocking position to prevent return of the hammer until the trigger is pulled, and ratchet means on said cylinder, a hand spring-biased toward said ratchet means to move the cylinder chambers step by step into firing position, and pivot means on said cocking lever mounting said hand thereon for reciprocatory ratchet-engaging motion as said cocking lever is moved during hammer-cocking operation.

2. The invention according to claim 1, said cylinder having a plurality of pawl stops, one corresponding to each chambered position, and a cylinder pawl successively engageable with said pawl stops to position each chamber successively in alignment with said barrel, and cam means interconnecting said cocking lever and said cylinder pawl for gradually releasing said pawl from its engagement with its associated pawl stop as said cocking lever is moved toward cocking position.

3. The invention according to claim 2, and a hammer blocking bar engaged with said pawl and movable into hammer blocking position by movement of said pawl out of engagement with a pawl stop.

4. An automatic revolver comprising a frame carrying a barrel, a rotatable cylinder mounted in said frame and having a plurality of chambers successively aligned with said barrel as the cylinder is rotated, and a hollow handgrip portion rigidly fixed to said frame; a gas cylinder communicating with said'barrel by a small port, a gas piston reciprocally mounted in said cylinder, a cocking drive means driven by said piston from an initial position and extending to the axial center of said cylinder, cocking means engaged by said drive means to cock the revolver when the gas piston is moved rearwardly, spring bias means normally retaining said drive means in said initial position disengaged from said cocking means, and a cam engagement between said cocking drive means and said cocking means of such configuration that the impulse of the drive means is transferred smoothly to the cocking means, said cocking means comprising a pivoted cocking lever spring-biased to a normal position against said cocking drive means, a forwardly spring-biased hammer engageable by said cocking lever during its rearward motion to move said hammer into cocking position, and trigger means having a sear portion for engaging said hammer in said cocking position to prevent return of the hammer until the trigger is pulled.

5. The invention according to claim 4, said cocking lever being independently returnable to its normal position by its spring bias after the hammer is cocked, and a gunsight notch on the cocking lever.

6. The invention according to claim 5, including a catch movable with said hammer, a trigger stop on said trigger engaging said catch in the rearward position of said hammer to which it is driven by the action of said gas piston, when the trigger is fully retracted, to prevent return motion of said hammer, said sear portion engaging said hammer when the trigger is released and said stop is disengaged, whereby continuous automatic action of the revolver is prevented.

7. The invention according to claim 4, and a thumbengageable knob on said hammer for independently cocking same Without rotating the cylinder.

8. The invention according to claim 4, and hammer bias means initially biasing said hammer in a floating position whereby inertia of the hammer carries it past said floating position when released from said trigger means from the cocking position, to fire the revolver.

References Cited in the file of this patent UNITED STATES PATENTS 515,064 Unge Feb. 20, 1894 2,560,292 Kauch July 10, 1951 2,863,249 Koucky Dec. 9, 1958 2,927,390 Lewis Mar. 8, 1960 FOREIGN PATENTS 14,130 Great Britain 1886 

